1. Field of the Invention
This invention relates to water shut-off devices and alarms used for detection of fluid leaks and notification thereof, specifically to an alarm system for storage hot water heaters which comprises an alarm housing, power supply leads inserted through the top of a hot water heater tank, a fluid collection pan positioned under the hot water heater tank, a fluid detection sensor associated with the fluid collection pan that is aligned with a small opening in the pan, and a pan sensor cable connected between the sensor and the alarm housing so that after only a very small amount of water has been collected in the pan, a portion of that water will pass through the small pan opening and via gravity, and then enter a water collection chamber in the fluid detection sensor that contains the exposed end of the pan sensor cable. Contact of water in the chamber with the end of the pan sensor cable completes an electrical circuit that initiates generation of a leak warning signal by the alarm housing, which has circuitry and components configured to provide prompt owner/operator notification in a variety of ways as soon as the connected fluid sensor is in contact with the threshold amount of water needed to complete the signal generation circuit. Owner/operator notification can be provided via audible means, visual means, and/or remote notification, such as but not limited to a signal transmitted through a home security device to a 24-hour security monitoring network. The alarm housing can be easily mounted on top of the hot water heater tank, or in the alternative can be mounted to a handy box or disconnect box located on a wall (or other surface) near the hot water heater tank. The lead wires inserted through the top of a hot water heater tank are placed in electrical communication with signal generating circuitry positioned within the alarm housing, and as a result of the alarm housing being hard wired, reliance on batteries is avoided, allowing the useful life of the present invention system to typically meet or exceed that of the associated hot water heater with little or no operator inspection or maintenance required. In addition, since the lead wires never have to be removed from the hot water heater tank, their connection can be made tamper-resistant. Also, the fluid detection sensor associated with the water collection pan positioned under the hot water heater tank is connected to the alarm housing via electrical wiring (hereinafter also called a “pan sensor cable”) that extends along the exterior surface of the hot water heater tank and is secured thereto in one or more places via small surface mounts to place it in an out-of-the-way position for reduced contact with surroundings. When water leaking slowly from a hot water heater tank first contacts the exposed end of the pan sensor cable positioned within the water collection chamber of the present invention fluid detection sensor, which occurs after only a very small amount of water has accumulated in the pan, an electrical circuit is completed that provides the audible signal, visual signal, and/or remote notification of leak detection so that prompt operator/owner action can take place to avoid water damage to surroundings and/or catastrophic tank failure. Reset of circuitry within the alarm housing will place the present invention system back into its leak detection mode.
2. Description of the Related Art
In residential storage hot water heating systems, about eighty percent of failures are in the form of slow leaks, which when multiplied by the large number of storage hot water heaters in current use can potentially lead to billions of gallons of water lost annually when such leaks remain undetected, and with even more water loss occurring if corrosion of the hot water heater tank is accelerated by slow leaks and results in catastrophic hot water heater tank failure. Since hot water heating systems commonly work for many years after installation without developing a problem, even when little or no owner/operator maintenance takes place (such as the recommended annual cleaning to flush sediments), and as a result it is uncommon for most owners or operators of storage hot water heater tanks to conduct inspections for slow leaks at any time other than in conjunction with the time during which an annual cleaning to flush sediments might take place. If slow leaks do occur and are not promptly detected, leaking water will accelerate the growth of mold on and around the hot water heater tank, all of which contribute to accelerated tank corrosion that will reduce its useful life. In addition, the risk of catastrophic tank failure is increased when corrosion occurs, where many more gallons of water can be lost, particularly if the water pressure in the cold water pipe leading into the hot water heater tank is strong and no one promptly becomes aware of the tank failure. Thus, there is a need for a device or system to monitor storage hot water tanks for slow leaks and provide prompt notification about them as soon as possible after such leaks start to divert water from the tank. The present invention system is configured to promptly detect slow leaks in a storage hot water heater tank, while also providing notification about the leak to the owner or operator of the tank via audible, visual, and/or remote notification means. As part of the present invention, power supply leads are inserted directly into the top of the storage hot water heater tank targeted for monitoring, where they remain during the useful life of the tank. Via use of a pan sensor cable and an alarm housing, the power supply leads are in electrical communication with a fluid detection sensor associated with a water collection pan positioned under the storage hot water heater tank. It is preferred for the size of the water collection pan to not to extend significantly beyond the footprint of the associated hot water heater tank and have a depth dimension sufficient for collecting water from slow tank leaks without damage to surroundings. However, it is not contemplated for the water collection pan of the present invention to have a fluid collection capacity sufficient to hold the entire contents of a storage hot water heater tank should catastrophic tank failure occur. When a small threshold amount of water collects in the present invention pan from one or more slow tank leaks, it preferably passes through a small opening in the pan that is aligned with a water collection chamber in its fluid detection sensor. The water collected in such a manner within the chamber contacts the exposed end of the pan sensor cable, completing an electrical circuit with components in the alarm housing that initiate the generation of one or more notification signals by the alarm housing that promptly provides owner/operator notification of the storage hot water tank leakage in an attempt to avoid excessive water loss and significant water damage to surroundings. In addition to owner/operator notification, shut off of electrical power and water to the hot water heater tank are also to considered within the scope of the present invention via existing technology, although not discussed in fuether detail within this disclosure. Since the present invention is also hard-wired with the hot water heater, reliance on a potentially forgetful owner/operator for periodic battery replacement is avoided. No other system is known that has the same structure as the present invention, functions in the same manner as the present invention, and/or provides all of the features and advantages of the present invention.